cicada air conditioning - Ford Forums

Gargoyle · 12-23-2003, 06:21

Howdy Pilgrims, got this bloody cicada sound coming from the passenger foot well (vent?) when the air con is on. It seems to vary in pitch and volume in relation to revs, this may be misleading though...any wild theories?

mongrelEB · 12-23-2003, 14:46

Probably a vacuum leak, either that or the fan has a noisy bearing.
If you pull out the glove box, you will see a vacuum fitting behind it with a heap of litle different-coloured tubes in it. One of these may be leaking, try pushing on them one at once while the car's making the noise and see if it stops :)

Alex

botch · 12-24-2003, 01:05

my bet is if it only does it with a.c on it wont be vacuum or fan motor related.

probably the sound of the gas going throught the TX valve (the square block thing in the engine bay side of the firewall with 4 a.c hoses going into it). The valve has tiny needle to reguate gas flow and will sometimes vibrate. You could try replacing it and re-gassing it if you can afford it, otherwise a top-up on the system might be a quick fix (if you can find someone that will top do a top up that is )

Gargoyle · 12-24-2003, 06:29

hmmm...suspicions duly noted my FF comrades. I hadn't considered either of these options. I though maybe a leaf had gotten into the plumbing and was rubbing against a fan or something. The noise has been intermittent ever since I got the car, but never this loud or consistent. Hehe here's me considering shoving a coat hanger up the nearest hole to see what happens!!

I shal sus things a bit further after I see whether Santa has brought me a tranny cooler or a strut brace

Rollin · 12-25-2003, 00:33

does it do it with the fan motor on or only with the actual ac compressor running? you say it varies in relation to revs - i think its your ac compressor - they tend to make a strange sound when they are getting on a bit or wearing out, or sometimes even if the wrong amount of gas is in the system.

get it re-gassed and see if it goes away, but if it doesnt i think you are up for a new compressor...

Gargoyle · 12-26-2003, 07:02

Well, the sound seems to get louder and faster the faster i go so maybe your right. Strange thing is, today I went for a run to Bribie Island. On the way there it made no sound at all, on the way back it was there but barely audible. Yesterday it was giving me the chronic sh*ts and a migrane. Go figure.

Rollin · 12-26-2003, 19:51

it is probably the compressor then, but not neccessarily because it is fubar.

if the pressure in the system is not right, ie to high or too low, then the compressor can get loud.

the pressures will be different day to day due to ambient air temp, in-car temp and road speed all affecting the temp of the gas at different areas in the system.

get it re-gassed, and see how you go.